Refer to the Exhibit.
Which correctly implements the relationships shown in the diagram?
A.
public class Y {
private Z[] z1and2;
public Y(Z[] z1and2) {
if (z1and2 == null || z1and2.length != 2) {
System.exit(1); // ERROR!
}
this.z1and2 = z1and2;
}
B.
public class Z {
private Y[] y1and2;
public Z(Y[] y1and2) {
if (y1and2 == null || y1and2.length != 2) {
System.exit(1); // ERROR!
}
this.y1and2 = y1and2;
}
C.
public class Z {
private Y y1;
private Y y2;
public Z(Y y1) {
if (y1 == null) System.exit(1); // ERROR!
this.y1 = y1;
}
public Z(Y y1, Y y2) {
this(y1);
this.y2 = y2;
}
D.
public class Y {
private Z z1;
private Z z2;
public Y(Z z1) {
if (z1 == null) System.exit(1); // ERROR!
this.z1 = z1;
}
public Y(Z z1, Z z2) {
this(z1);
this.z2 = z2;
}